Hi all,
Sometime ago I was looking for something other than a blanket to block out surrounding light from the eyepiece while viewing so I came up with using a round black table cloth folded in two and had my wife sew it on the edge along with some black canvas handles. It really works well and below are a few pictures.
The table cloth cost $12 from WM

Bill,
It does help keep you warm when it’s cold but you have to watch your breathing, it’s easy to fog your eyepiece if your not careful. When the table cloth is folded as I indicated it really does block out the light even a full moon.